The structural phase transition in under uniaxial stress in the [110] direction: a calorimetric study

Gallardo, M. C.; Jiménez, J.; Valero, Constantino; Salje, Ekhard K. H.

doi:10.1088/0953-8984/8/1/009

Cited by 21 publications

(15 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The measurements were made at a constant heating rate of 0.06 K h 1 . The transition causes a small C P step at 105 K. These data agree well with earlier measurements (Gallardo et al, 1996).…”

Section: Results For Srtiosupporting

confidence: 92%

Phase transitions in perovskites near the tricritical point: an experimental study of KMn_1–xCa_xF₃ and SrTiO₃

et al. 2000

View full text Add to dashboard Cite

We present experimental data for the Pm3m I4/mcm phase transitions in the perovskite crystals KMn 1 x Ca x F 3 and SrTiO 3 . Comparison of calorimetric data (latent heat and specific heat) with order parameter data (measured with X-ray rocking methods) indicates that these transitions follow meanfield behaviour, and may be described using Landau potentials where the free energy expansion includes terms up to Q 6 . This potential is characteristic of transitions close to the tricritical point. Comparison of the behaviour of SrTiO 3 and KMnF 3 indicates that KMnF 3 is closer to the tricritical point; a small amount of substitution of Ca for Mn causes the transition to cross the tricritical point from first order to second order behaviour.

show abstract

Section: Results For Srtiosupporting

confidence: 92%

Phase transitions in perovskites near the tricritical point: an experimental study of KMn_1–xCa_xF₃ and SrTiO₃

et al. 2000

View full text Add to dashboard Cite

show abstract

“…20 Nevertheless the coincidence of data obtained under 0.3 and 4.5Ϯ0.1 bar uniaxial pressure can be considered as proof of the reproducibility of our measurements. Now we will discuss the behavior of the specific heat data in the transition region.…”

Section: Resultssupporting

confidence: 56%

First order transitions by conduction calorimetry: Application to deuterated potassium dihydrogen phosphate ferroelastic crystal under uniaxial pressure

Gallardo

Jiménez

Koralewski

et al. 1997

Journal of Applied Physics

View full text Add to dashboard Cite

The specific heat c and the heat power W exchanged by a Deuterated Potassium Dihydrogen Phosphate ferroelectric-ferroelastic crystal have been measured simultaneously for both decreasing and increasing temperature at a low constant rate (0.06 K/h) between 175 and 240 K. The measurements were carried out under controlled uniaxial stresses of 0.3 and 4.5±0.1 bar applied to face (110). At Tt=207.9 K, a first order transition is produced with anomalous specific heat behavior in the interval where the transition heat appears. This anomalous behavior is explained in terms of the temperature variation of the heat power during the transition. During cooling, the transition occurs with coexistence of phases, while during heating it seems that metastable states are reached. Excluding data affected by the transition heat, the specific heat behavior agrees with the predictions of a 2-4-6 Landau potential in the range of 4–15 K below Tt while logarithmic behavior is obtained in the range from Tt to 1 K below Tt. Data obtained under 0.3 and 4.5 bar uniaxial stresses exhibit the same behavior.

show abstract

“…Within a 246 potential, this could be interpreted as a change in the importance of the elastic energy term that renormalizes the coefficient B. In STO, the study of the transition under an uniaxial stress applied along [110] C has shown that the transition got closer to second-order under the applied stress [50]. The first to second-order crossover in PbTiO 3 under pressure [51], as well as the second-order character of the cubic-tetragonal transition in KNbO 3 under pressure [16], provides another example of a pressure-induced change in the nature of a phase transition.…”

Section: Comparison Against High-pressure Datamentioning

confidence: 99%

Pressure-temperature phase diagram ofSrTiO3up to 53 GPa

et al. 2010

View full text Add to dashboard Cite

We investigate the cubic to tetragonal phase transition in the pressure-temperature phase diagram of strontium titanate SrTiO3 (STO) by means of Raman spectroscopy and X-ray diffraction on single crystal samples. X-ray diffraction experiments are performed at room temperature, 381 K and 467 K up to 53 GPa, 30 GPa and 26 GPa respectively. The observation of the superstructure reflections in the X-ray patterns provides evidence that the crystal undergoes at all investigated temperatures a pressure-induced transition from cubic to the tetragonal I4/mcm phase, identical to the low-temperature phase. No other phase transition is observed at room temperature up to 53 GPa. Together with previously published data, our results allow us to propose a new linear phase boundary in the pressure-temperature phase diagram. The data are analyzed in the framework of the Landau theory of phase transitions. With a revised value of the coupling coefficient between the order parameter and the volume spontaneous strain, the model built from pressure-independent coefficients reproduces satisfactorily the boundary in the phase diagram, but fails at reflecting the more pronounced second-order character of the pressure-induced phase transition as compared to the temperature-induced transition. We propose a new Landau potential suitable for the description of the pressure-induced phase transition. Finally, we show that particular attention has to be paid to hydrostatic conditions in the study of the high-pressure phase transition in STO.

show abstract

The structural phase transition in under uniaxial stress in the [110] direction: a calorimetric study

Cited by 21 publications

References 27 publications

Phase transitions in perovskites near the tricritical point: an experimental study of KMn_1–xCa_xF₃ and SrTiO₃

Phase transitions in perovskites near the tricritical point: an experimental study of KMn_1–xCa_xF₃ and SrTiO₃

First order transitions by conduction calorimetry: Application to deuterated potassium dihydrogen phosphate ferroelastic crystal under uniaxial pressure

Pressure-temperature phase diagram ofSrTiO3up to 53 GPa

Contact Info

Product

Resources

About

The structural phase transition in under uniaxial stress in the [110] direction: a calorimetric study

Cited by 21 publications

References 27 publications

Phase transitions in perovskites near the tricritical point: an experimental study of KMn1–xCaxF3 and SrTiO3

Phase transitions in perovskites near the tricritical point: an experimental study of KMn1–xCaxF3 and SrTiO3

First order transitions by conduction calorimetry: Application to deuterated potassium dihydrogen phosphate ferroelastic crystal under uniaxial pressure

Pressure-temperature phase diagram ofSrTiO3up to 53 GPa

Contact Info

Product

Resources

About

Phase transitions in perovskites near the tricritical point: an experimental study of KMn_1–xCa_xF₃ and SrTiO₃

Phase transitions in perovskites near the tricritical point: an experimental study of KMn_1–xCa_xF₃ and SrTiO₃